I had the same problem in high school, also running around 180 or so. Pretty big for a high school sprinter. Have you ever thought of running the 200m or 400m instead?
And you don't have a need for a second weights day. You could do perhaps 3 weight sessions per 2 weeks instead of 2 per week, but your strength doesn't appear to be lacking (though I'm taking your word that those 435lb squats were full squats).